The accumulation of ice on the wing surfaces of an aircraft prior to takeoff can adversely affect the ability of the craft to fly. Excessive ice buildup, if undetected, may cause an aborted takeoff or crash.
Currently the presence of ice on the wings of aircraft is detected by visual inspection. Such inspection may be unreliable particularly when visibility is impaired by fog, falling snow, freezing rain and/or by darkness. Often, because of delays, it is not possible to de-ice the aircraft shortly before takeoff. For these reasons there is always some risk of a dangerous accumulation of ice prior to takeoff in wintry conditions.
In the past, others have developed ice detectors for aircraft. For example, U.S. Pat. Nos. 4,095,456; 3,996,787; 3,976,270; and 4,053,127 disclose devices for detecting ice accumulation. However, these devices check for ice accumulation during flight at a leading edge of an aircraft surface such as at the leading edge of a wing or nacelle. These devices are not adapted to check for ice on the lifting surfaces of the wings prior to takeoff.
In addition, most of these prior art devices detect only the rate of ice accumulation. They do not detect total accumulation which is critical in determining if the lifting ability of the wings of the aircraft has been impaired.
Thus, there exists a need for an aircraft icing detection system that accurately and reliably detects accumulation of ice on the wings of an aircraft prior to takeoff.